1. Field of the Invention
The present invention relates to an image forming apparatus and a belt unit, and more particularly to an image forming apparatus and a belt unit attachable to and detachable from the image forming apparatus.
2. Description of the Background Art
A background image forming apparatus, such as a copying machine, a printer, or a facsimile machine, generally includes a plurality of photoconductors to form a color image on a recording sheet. The photoconductors respectively carry toner images in yellow, magenta, cyan, and black colors which are formed with yellow, magenta, cyan, and black toner according to image data. The toner images formed on the photoconductors are superimposed and transferred onto an intermediate transfer belt to form a color toner image on the intermediate transfer belt. The color toner image formed on the intermediate transfer belt is further transferred onto a recording sheet to form a color image on the recording sheet.
The intermediate transfer belt is included in an intermediate transfer unit which is attachable to and detachable from the image forming apparatus. To insert the intermediate transfer unit into the image forming apparatus, an operator of the image forming apparatus holds guided members disposed on the intermediate transfer unit and engages the guided members with guide members disposed in the image forming apparatus. The operator then pushes the intermediate transfer unit into the image forming apparatus in a horizontal direction. Thus, the guide members guide the intermediate transfer unit into the image forming apparatus via the guided members.
The intermediate transfer belt is looped over a plurality of rollers of which shafts are supported by two opposed frame brackets. The guided members are disposed along outer surfaces of those two opposed frame brackets so as to be extended in a direction perpendicular to a lengthwise direction of the roller shafts. Therefore, the intermediate transfer unit may be inserted into and removed from the image forming apparatus only in a direction perpendicular to the lengthwise direction of the roller shafts.